Various containers and apparatus are used for containing and dispensing liquids in laboratory settings. Useful laboratory liquid containers include tubes such as centrifuge tubes and microcentrifuge tubes. Microcentrifuge tubes come in various volumes from about 0.1 mL to about 2.5 mL and are among the most versatile laboratory liquid sample containers. Microcentrifuge tubes often include a cap connected to the tube and conveniently fit various racks and blocks that, for example, place the tubes in arrays compatible with heaters, pipettors, and culture plates. Due to this convenience, microcentrifuge tubes are used in many laboratory operations, such as shaking, heating, centrifuging, and the like, that require that the tube be capped to prevent spilling or evaporation of fluid in the tube. This requires capping and uncapping of the tube before and after each of these operations. Capping and uncapping takes time and provides an opportunity for spilling or contaminating the contents of the tube.
Liquids are most often added to and dispensed from tubes, such as microcentrifuge tubes, using a pipette or pipettor. Pipetting requires that the tube be uncapped and the pipette or pipettor be inserted into the opened tube. Inserting a pipette, a pipettor or other liquid handling device into the tube is inconvenient in several respects. First, the tube must be repeatedly capped and uncapped for each operation with the pipette or pipettor. This repeated capping and uncapping slows procedures using the tube, increases the likelihood of spilling or otherwise contaminating the fluid in the tube, and is generally inconvenient. Second, insertion of a foreign object such as a pipette or pipettor into a sample in the tube allows contamination of the sample by a dirty pipette or pipettor. Such contamination can waste a valuable sample, give erroneous results, or require an expenditure of additional time and materials to prepare a duplicate sample.
What is needed is a liquid handling tube, such as a microcentrifuge tube, that provides for dispensing its fluid contents without uncapping the tube and without inserting a liquid handling device into the tube.